Santa Catarina`s Fort represents one of the last Philippine military constructions in Algarve.

Considered the best place to defend the bar of the river Arade, Santa Catarina`s Fort was built where already existed a small chapel dedicated to St. Catherine of Alexandria, in which still subsists a primitive Gothic portal inside the fortification. Although designed in 1621, the construction began only eight years later, in 1629, and ended in 1633. From the initial seventeenth-century project, only remains the main façade, organized in three symmetrical bastions, where the central one is backward. It has thick pilasters and lintel with large decorative stones, which gives the building monumentality and contrasts with the dominant horizontal.

Santa Catarina`s Fort was significantly damaged by the earthquake of 1755 and therefore was object of a recovery and reconstitution work. Later, already in the twentieth century, within the project of the tourist development of the “Barlavento” this fortress underwent a new deep remodeling. The interior was divided between an office of the Fiscal Guard and of the Port authority of Portimão and a belvedere. This last one, already in the decade of 60, occupied the zone where originally the military equipment laid down. In these works, part of the cliff on which is the fort was reinforced with modern construction, which allowed an extension of the lookout area. At the same time, the progressive silting of the bar and the consequent increase of the sand, allowed the use of all the structure as a support facilities to the Rocha beach, benefiting of great views over the Arade river, the city of Portimão and its marina.